Power transmission



Sept. 30, 1952 H. o. SCHJOLIN POWER TRANSMISSION 5 Sheets-Shet 1 FiledAug. 3, 1945 Imnentoli 974272: (QJcfiz/olzn H. O. SCHJOLIN POWERTRANSMISSION Sept. 30, 1952 5 Sheets-Sheet 2 Filed Aug. 3, 1945 Sept.1952 H. o. SCHJOLIN 2,612,061

POWER TRANSMISSION Filed Aug. 3, 1945 5 Sheets-Sheet 3 Ihwentor 9/0723(9. Jc bjblz'n attornegs 5 Sheets-Sheet 4 H. o. SCHJOLIN POWERTRANSMISSION Zmnentor (Ittomegyb Wm. "WW J W Sept. 30, 1952 Filed Aug.3. 1945 P 30, 1952 H. o. SCHJOLIN 2,612,061

POWER TRANSMISSION Filed Aug. 5, 1945 5 Sheets-Sheet 5 3nnentor 92m, digMin w f y attorney Patented Sept. 30, 1952 rowaa TRANSMISSION Hans 0.Schjolin, Birmingham, Mich., assignor to General Motors Corporation,Detroit, Mich., a corporation of Delaware Application August 3, 1945,Serial No. 608,787

This invention relates to motor vehicles, and in particular to those inwhich the power plant assemblies are located at the rear for higherefficiency in power transmission and for compact and accessiblemechanism, this equipment being for large vehicles such as busses,trucks and tractors.

The invention relates, in part to an arrangement of the drive mechanismwherein th engine is transversely mounted, parallel to the driving axle,and the intervening variable speed transmission which may include afluid torque converter is placed at an angle between them, and taken forbest efficiency and accessibility. It relatesfurther to the selectivecontrols for such an assembly in which there is drivers choice betweenmanual and automatic operation.

It is an object of the invention to provide a" positive couplingmechanism which shall enable the operator to maintain control of thevehicle atall times and under all road' circumstances while beingenabled to enjoy automatic selection of drive speed ratio, as distinctfrom other devices wherein freewheeling couplings and effects haveeliminated the engine braking factor. As a,

supplemental object, the present disclosure provides interconnectingmeans with the other controls for transmission speed ratio, which assurethe correct conditions for the operation of the said-positive drivecoupling. 7

An additional object is to provide in the transmission mechanism, meansfor completedecoupling of the reversedriving train during forward drive,preventing waste of power and churning of the transmission lubricant. Itis likewise an object of the invention to decouple the counter gear orreduction drive train positively during forward running which has thesame advantages.

A further object of the invention is to provide automatic forwarddriveratio controlwhich shall operate by selective actuation of frictionclutch members and by jaw clutch members with interlockingmeans betweenmanual and automatic controls for the members, safeguarding completelyagainst loss of the control operation .by the driver, as stated above,and which shall eliminate automatically, a shift into-the higher speedratio when'the drivin conditions and torque demand are both low. Thisinterlocking control is believed importanti An additional object is theprovision of a manual control which operates to prevent release of, andto sustaihthe engagement of the direct coupling clutch of the assembly,when desired, for driving in mountainous country, which con- 28 Claims.(Cl, 74-645) trol enables the hydraulic drive portion ofth'l mechanismto function as a brake. f

Further and additional objects and advantages will appear in thespecification and description of; operation herewith. I I I g Figure 1is a longitudinal sectional view of the transmission assembly of theinvention, resem bling the structure of my Serial-No. 507,204 filed,October 21,1943, but differing therefrom in c er tain importantparticulars'as will be understood further. 'o I Figure 2 is an outlinedrawing 'of the upper; portion of the assembly shown in Figure i,. toindicate the relationships of the external controls" for theclutchingimechanism. I.

Figure 3'is a detailed view of the link'construcfl tion shown in Fig. 2,and sectioned in part for. clarity. Figure 4 is a longitudinal sectionthroughthe. forward and reverse gear box shown in Fig. 1, but taken togive the details of the relationships among the gears of that assembly.

Figure 5 is a schematic diagram. of the auto matic and manual controlsystem with especial; reference to the superimposed controls for thelink structures of Figs. 2 and 3. I 1 Figure 6 shows in outlinethegeneral. arrange ment of a drive assembly equipped with the in?vention, showing in particular its external control linkages necessaryto. carry out the operational-Q sequences of theFig. 5 controls. Figure7 is a perspective view in part section of the forward and reverseselecting mechanism, controlling a portion of the linkage'shown Fig.6,-andlocated in the drivers station. i 'f T Figure 8 is a schematicview of a structure to be added to that shown in the other fi uresionthe purpose of providing. assured extra braking effect for operationin'hilly country. a In Fig. 1 the engine shaft lis attached to mi wheel2 and its flange is boltedto the input bevel gear jackshaft flange 5spline'd at 3 to the-jackshaft 4, the latter being supported inbearingsfl" and 8. Worm gears 10,10 drive cross-shaft,,l.i","i drivingthe supply pump P as shown in F directly from the engine.Jackshaftbeveltee l2 overhang i a pace formed by portions of";

the housings mo and |noa. The engine casing sis" is bolted to housing atX-X, and the Jacki shaft housing I00a is supported m'housingiotgby.bolts as. Housing I00 enclosesthe dnve'f 'geei'; assembly G and thetransmission input bevel'gear" l3 meshing with l2... l of. The turbi eand clutch housing I000. partsiiitif Y-Y. The end plate loob'isbolted-to latent" 2-2. The rear output drive portion of the gear housingI is closed by end-plate I00d.

The cap I00e holds the end bearing for the transmission in place.Jackshaft housing I00a. is bolted to casing I00. The assembly of 99,I00, I00a, I000, I000, IOIld and I00e provides a substantial and sturdyalignment of the centers of the shafting and rotating parts, the wholeassembly being rigid with the engine.

The transmission shaft 20 is the input member for the forward andreverse gear, and is mounted in bearings I04 and I05. Shaft 20 issplined for clutch hub I6 of direct drive clutch plate I5, and splinedfor jaw clutch slider 30.

Power input sleeve I9 is fixedto bevelgearlt and is bolted to clutchdrum' 2I having presser plate 22 operated between the inner face of theweb of drum ill and attached fulcrum ring 23.

Disc spring 24 is shifted by movement of the bearplate II mounted onclutch hub I4 which is.

splined to sleeve I8 attached to turbine impeller I.

friction clutch system is shown in my Letters Patent U; S. 2,341,163.issued February 8. 19px.

"Sleeve I9 is attached to drum 2i, having the movable plate 22 forshifting the clutch gripping force tc pinch clutch driven plate I ofsolid shaft 20, or release same and clamp plate I? of h'ollowshaf't I8.The torque converter T consists. of an input impeller I, output turbinerings 0, QgandfQs-and reaction vane ring R, and Impeller L is attachedto hollow shaft I8 of clutch plate H; the output turbine rings 0, On

and 0e are attached to flanged clutch jaws"3l,'

artd'thie reaction vanes R and Ba are integral with the casing I 00.

Shaft is splined to aceommodateslider having jaws 32 mating withjawsi3l.

Fork II, pivoted at'42, meshes and demeshes the jaws 3| and 32. Theclutch jaws are inclined on their adjacent facing tooth endsso that when32f arelrot ating faster. than jaws 3|, if the slider 30 is moved towardmesh. a rejection of engagement occurs byreason of the axial forcedeveloped by the inclined tooth ends acting as cains', .However, ifthejawscome to synchronism.

thefrej ection force disappearsand the teeth mesh upon-finding registry.If jaws 3I are, rotating raster than 32, meshing motion of slider 30would cause a crash engagement, which condition is a era e inthe'operation of the controls,de-. scribed following.

The applicants Letters. Patent, U. S. 2,351,153 issuedFebruary 8', 1944,in Figsfifand 7 shows an eng ,efiywheel Ia equipped with a dual clutchcontrol, loaded by a. disc spring I'I0 operated by sendin bearing from ashaft I80. This clutch system connects the engineto the output sleeveQIor totheimpeller 40 of the torque converter.

'The present dual friction clutch system and controlresembles thisearlier device, but avoidsthe' difficulties experienced with theone-way.-

clutch'l8, I9, 2I by substituting, therefor the jawfclutch 3I 32,controlled by, the mechanism which controls the, dual friction clutch.With the present device, the operation of the dual an themasimultaneously controls the jaw clutch M1732, so that disengagementofthe turbifi'e lutch plate I I, automatically disengages the la lutch,and viceversa.

The drum 2i supports presser plate22 for axial traveland shaft 20carriessplined hub it. and ls ssgd s I iq gi nepn haf 20 s h e l 4 shaftI8 carrying splined clutch hub I4 attached to clutch disc II. The clutchsystem is made alternatively operative for engagement of the clutchdiscs I5 and I! but in addition to the above-noted patent disclosure,the jaw clutch 3I32 is provided with a cooperative control.

Fig. 2 is an external view of the operating mechanism for'the clutchsystem of Fig. l.

Shaft 50 is supported in the casing I00, and carries external lever SIand internal fork 52 for moving the collar pins 53 which shift the inneraction portion of the clutch loading disc spring 24. Rocking the lever5| anti-clockwise causes the disc spring 24 to exert a pull to the lefton the presser plate 22 of Fig. 1 clamping disc I! of hollow shaft I8and imparting engine rotation to the impeller I. Rocking lever 5Icockwise in Fig. 2 clamps disc I5 between presser plate 22 and the drum2I imparting engine rotation to solid shaft 20 of Fig. 1 for directdrive.

Shaft 42 mounted parallelto shaft, 50 carries attached fork 4| for jawclutch slider, 30,,and its. external arm 6| is moved with lever arm 5|ofv shaft 50, through the agency of flexible, link mechanism L.

Fig. 3 shows how this link mechanism is con-- structed. Arm 5| isrecessed for clevis pin 64 of clevis barrel 65, screw capped at 66 tocontain springs, 61 and 68, and plunger rod 69, the plunger head I0being located between the inner ends of the springs. The rod 69 hasclevis 12 pivoted, to arm SI of shaft 50 of the jaw clutch fork 4I.

Anti-clockwise movementof lever arm 51 to engage the turbine clutchplate I'I exerts a pull to the right. in Fig. l on the jaw clutch slider30, the lost motion spring 68 compressing, and yielding until the jawteeth 3 I.32 mesh at synchronism, when the turbine input and output areeach then connected to engine and load shafts, respectively.

During a synchronous mesh rejection by the jaw teeth 3| and 3,2, thesprings 6768 of' the.

device L yield and as mesh occurs, they rte-center the plunger head 10.

Clockwise motion of lever arm 5| to disengagethe turbine clutch I! may.continuaso thatwhile, torque on the flat sides of teeth 3 IH32issufficientv to resist demeshing, theremoval of torque on the impeller Ileaves onlymthe drag torque of the spinning output vane wheels to beovercome. For

the case of the reverse torque emoiency of;-a turbine torque converterbeing oflow valuerthe demeshing force requirement-for sliderv is: only."

a few pounds, so that if desired, this operation could proceed manually.Such a; manual means;

to move a similar slider manually-=is ;commonly known in this art,-

Experience with the above described drive and control mechanism hasshown that the, simultaneous control of the turbine input clutch I1 and;the output clutch 3I.-32 is foolproof and simple.;. Sinceat theengagement interval for theturbiney the vehicle is either standingstill, or in motion, with the output shaft tending to slow down-,so

as to necessitate a shift from direct drive. the. helical angle on thecamming ends of the, jaw teeth istaken so that mesh rejection occurswhenthe output shaft 20 is rotating faster than the turbine output rotors R.,The closing ofthe' turbine input clutch IT, with releaseof the direct;

drive clutch I5, permits the vehicle load to slow synchronous; speedwith laws 32' rotating with shaft 20.:

The forward and reverse gearbox shown in detailin Fig. 4 consists ofmain shaft 20, and output shaft I20 supported in the bearings shown, in.

casing I00, and piloted by bearing 12 i The shaft 20 has afiixed gear 35and ring of teeth 36, while output shaft I20 has affixed toothed member31 upon which slider gear 38 is mounted for unitary rotation- Thecountershaft 40 supports sliding gear 43' two rings of teeth 41 and 48.Body 46 does notslide axially. The centers of shafts 20 and 40, 45- andthe axial spacings of theg'ears are'so taken that slider gear 33 ofshaft I20 may mesh with teeth 48 of idler 45 when the slider 38 is movedto the right. The counter gear 43 of shaft 40 is always mashed withteeth 47 of the idler 46. Shifting of slider 33 from the direct driveposition shown, to the right, dlsengages the internal teeth of slider 34from teeth 36 for neutral, subsequent movement to the right by slider 33pulls gear 43 into mesh with gear 35, when the teeth of 43 and 45 haveentered, the slider teeth 38 mesh with idler teeth 48.

Indemeshing reverse, the slider teeth 38 first disengage'from teeth 48,then counter gear 43 refleases from idler teeth 41 as the slider movesto full engagement of the direct drive teeth 34 and 3B.

.This method avoids the churning losses ordinarily found in standardgearboxes, by having the counter gear and idler assemblies come to restduring forward drive, and the staglngof the pick-up of the first idlergear prior to the connecting of the other idler gear with the outputshaft is a useful feature in that it permits prior unloaded rotation ofbody 46 for mesh of 38--48, which latter occurs with the vehiclestanding still, and with no torque on the shaft 20.

The external control for the drive mechanism may be simple, and bereduced to the operation of only one control actuator element, in thepresent instance, lever arm for direct drive shift.

There is one precaution to observe. When shifting from converter driveto direct drive, it is expedient to assure full release of .the jawclutch 32 prior to engagement of direct drive, otherwise it may bediflicult to declutch thejaw slider 30, since the drag torque on theoutput rotor could rise with increased engine speed to nearly maximum.This is obviated by adjusting the throw distances and timing ofthecontrol lever and link system, and by having the springs 61 and 68 of agiven force and abutment factor so that th desired sequence of actionobtains.

The net motion for shift between converter and direct drive is small forthe upper end of lever arm 5| as noted by the markings-in Fig. 2.

. Fluid servo cylinder housing 80 is bolted to casmagnet valve V,thepiping H0 connecting tank- A to valve V and piping II! to servo feedline I I2. I

The fluid servo system utilized to actuate the forward variable speedratio changes also is used" to overcontrol the engine throttle, and torestore same at completion of the shift action. Th ratio controls areautomatic, by output speed governor, modified by accelerator pedalposition, and1 the control functions are executed electrically.

The control system herein resembles that of my Letters Patent U. S.2,322,479, issued June 22, 1943. In this patent, I show an electricald'ethrottling device serving the purpose of facilitating mesh and demeshofa jaw'clutch, with a switch interlock system normally de-energised andactivated only when. a shift interval is in progress; and an automaticaccelerator pedal and governor ratio selection arrangement coor'dinating pedal position and vehicle speed.

In my application for Letters Patent, Serial No. 507,204 filed October21, 1943, I show a fluid: pressure dethrottling and restoring device.operated by the fluid pressure actuating the ratio: clutch shiftermechanism, utilized for speeding: up the shift interval and avoidance ofhigh dif1-. ferential speeds on the clutch members, :and an automaticratio selection system controlled byl; vehicle speed and by acceleratorpedal position.-. This application shows a control system more: nearlyresembling that of the instant disclosure; The latter includes some newfeatures designed to render the operational control more exact andbetter adapted to the problems involved in han-. dling large vehicles,based on experience withthe preceding described forms. A method ofoperation of this double clutch control apparatus is also described inmyU. S. Letters Patent No. 2,308,113, filed October --4,' 1940, and issuedJanuary 12, 1943, and shown: in Figure 6 of that patent. Admission andcontrol of fluid pressure to the. working face of piston 82 is obtainedby the ar.-.: rangement of Figure 5, a diagram of the fundamentalelements and units required. a I The clutch shifting piston B2isshownin-cylinder 30 ready for rocking the clutch operating: lever 51 towardthe position in which the collar:

25 of Figure 1 shifts the spring 24 .to load clutch.

plate I5. l. Energisation of the magnet valve V, such asis shown in Fig.3 of my U. S. LettersPatent No. 2,322,479, causes delivery ofreservoirsupplied pressure tothe cylinder for loading thepistorr 82 againstspring 83, and de-energization causes shutting off of the reservoirpressure and re-- leases pressure from cylinder 80, topermitspring.- 83to shift the piston 82 to the left. The magnet valve shown in Fig. 3 ofmy prior Patent U. S. 2,322,479 is composed of coil- I79 which whenenergised by current admits pres-=- sure from pressure feed line I20 toclutch servo cylinders H5 and [30, and when the circuit is broken, shutsoff the feed pressure and exhausts: the clutch servo cylinders I25 and'The' valve V herein similarly admits fluid pressure from pipe H0 toclutch servo line H2 when current is delivered to its coihand similarlyex'== hausts the clutch servo line H2 and connectedpassages when thecircuit is broken. It has n ot been deemed necessary to show theinteriorpartsof the magnet valve V since they are exactly the same as in theaforesaid Figure 3 of applicants Letters PatentU. S. 2,322, When -thec'ircuit from the electrical power source is closed connecting valveV-the-magnet coil of valve; V the reservoir pressure ofline no isadmitted. to line: m as noted above, and when the circuitv is broken bopening of one of switches 8-5, S-3,LS-4 or S, the valve resetsso as tovent the line H2 at the exhaust tube (not numbered) and shut off feedline H0.

Electric current supply to the magnet valve V passes. through stopswitch. S and gear lever switch S from the battery; and also passesthrough overrule switch S and governor switch 5 To obtainpositiveneutral, the piston rod 8i is stopped at neutral by the swing stop HI!which intersects the travel of lever 51 when airpres'-' sure shifts: thepiston 82 toward direct drive position, and when current flows insolenoid I08.

Fluid pressure delivered by magnet valve V to line 'l I2 reduces theengine throttle setting, the small piston H4 of cylinder I I5 havingrod. I13 linked to bellcrank IIl pivoted to rod H9 of the throttlecontrol, and operating through the body of. spring. I2I. The clutchoperating cylinder 82 isported to air line H3, connected to the leftportion of the throttle control cylinder H5, so that when the clutchpiston 82 moves to the right beyond the port of line I I3, the pressuremay flow to' theleftward face of piston I I l, equalizing that exertedon" its rightward face, whereupon the restoring-spring I2 I returns thethrottle rod I I9, bellcrank H1 and rod IIB to original position.

Electric current in one path passes through the master switch S,convenient to the operator, to the governor switch S overrule switch Sand magnet valve V; the other path leading from the battery "hot" sideto the gearshift lever switch S solenoid: stop switch S and magnet valve.V.

a For governor-overruling control, the accelerator pedal 200, operateslever rod 202 bellcrank 203 and the rod 204 of lost-motion device U, theplunger of which is attached to rod 205 of arm I I") of bellcrank I I"!controlling the throttle rod H ll. The springs I2I" normally transferthrust between rods 284 and 235.

At full throttle setting, the pedal 230 strikes overrule spring 22!]mounted under it on the floor board, which increases the pedal resistingforce, butthe lost motion device U opens the overruling: switch Sbreaking the circuit to the governor and magnet valve V, which causes atransfer of drive from direct-drive clutch plate I5 to torque converterplate i1.

When the vehicle is-at rest, engine running, with the operators masterswitch S normally closed, the gear lever 240 of Fig. 5 being moved toforward drive position, engages the slider 38 of Fig. 4with the teeth 36of. member 35.

Depression of pedal 28!? to advance the engine throttle causes thetorque converter to deliver torque to shaft 20, since clutch plate I! isnormally engaged.

The governor 258 of Fig. 5 driven by gear 50a. of Fig. 1 closes switch Sthe battery current passing. through normally closed overrule switch Sto magnet valve V, which being energized, opens reservoir pressure tocylinders 80 and H5. The clutch piston 82 moves right to rock lever 5-I'to release clutch plate IT and engage direct driveplate I5 while pistonIIA first moves left in cylinder I I5,,to close the throttlemomentarily- As soon as piston 82 uncovers the portof line I I3, the:air pressure equalizes on the faces of piston H4, and spring I2 Ire-opens the throttle.

The drive continues indirect drive, unless the speed of governor 250falls sufi'iciently to open the switch 8*; whereupon the: magnetvalve'clrcuitzis' broken, and the valve V shuts off the reservoir andreleases. the pressure in clutch cylinder 82,-so that spring 83 resetsthe clutch arm 5| and collar 25 of Fig.1 to .load clutch plate I! fordrive through theconverter. i

Momentary idlingof the throttle duringu'pshift to direct drive. by meansof the control serves to shorten the shift interval during which. excessdrag wear of the friction clutches wouldv otherwise occur.v Experienceshows that it is notnecessary to apply the reactive control. upon theengine throttle during the downshift to converter drive, with this driveconstruction.

Moving: of the accelerator pedal 290 to beyond fullthrottle may at anytime break the circuit:-

to the magnet valve V, by opening the overrule switch S andthereby' setaside the action of the governor 25!]. The driver therefore, has: theoption of initiating downshift to converter drive by pedal advancingmovement, due to thefeel. provided by overrule spring 220. The connec-.tion of the pedal 230 to the lost-motion deviceU, and to the overruleswitch S and the force of spring are soarranged that the operator feelsa. definite resistance to. further travel of pedal 200, just before themechanism would open switch S This pedal-overruling action may beadjusted to occur-at full throttle setting; beyond, or somewhat below,in accordancewith. the selected drive and engine characteristics. Asdescribed. again, a preferred arrangement is to have thedownshift-by-pedal effect occur somewhat beyond the full throttle pedalsetting.

While the fluid pressure is sliding the piston 82 to the rightwardposition in Fig. 5 as for direct drive, the swinging stop It]? may abutlever 5| while solenoid switch S is closed at a travel point i of pistonrod 8i equivalent to a release position for both clutch plates I5-I'I.Closing of switch S energizes I08, as the gearlever 240 is moved.

The above described disclosure represents a continuation in part of thesubject matter of my application for Letters Patent, Serial. No.299,643, filed Ocober 16, 1939, in particular the showing ofv Figures 16and 17. p 7

Referring to Figures 6 and 7, rod 233 is connected to bellcrank lever23I of Fig. 7, pivoted torod 232v extending through the floorboards andpivoted toarm 233 of part 234 of Figure 7; and rocks bellcrank 235pivoted to rod 236 having connection with the arm of shifter fork 237.

The gear lever 240 of Figure '7 is fastened to shaft 239 rocking withmounting 234 located forward in Fig. 7, at the operator's station. Thelever 240 and member 234 rock fore and aft, the pivoted mounting of thelever 26!! permitting a small lateral motion of the member 234. Thelever 248 is guided in the E-slot of the upper portion'of the'casing 238for reciprocation, and for lateral motion into the slot passages "F, Nand R for-forward,v neutral and reverse shift operaion.

The switch S of Fig. 5 is supported adjacent the lever 240, which isbiased toward the gear station positions by spring 240a. The swingingstop I07 of S always protrudes in the path of the lever BI and rod 8i,whenever the gear lever 240 is in the left, or continuous portion of theE-slot, with switch S closed. This halts the piston 82. of cylinder inmid-position or neutral, as the pressure to the left of the piston82 inFig. 5 causesit to shift to the right.

The lever 240 thru rod 230, mechanically operates slider 38 of Fig. 4 byappropriate 1inkages,.

and its action constitutes an improvement over the arrangement of Fig. 9of my Letters Patent U. S. 2,322,479.

The diagram of Fig. 5 shows a swinging stop 25| pivoted to block therelease of jaw clutch slider 30 so that the driven members of the fluidtorque converter may be required to rotate when the controls are set fordirect drive under overtaking torque, to provide braking effect.

Fig. 8 shows a mechanical'linkage between the lever 260 in the driversstation and the swinging stop 25l located on the gearbox adjacent lever6| of shaft 42 which controls the jaw clutch slider 30. The short arm260a of lever 260 is pivoted to rod 251 of bellcrank 256 operating rod255 bellcrank 254, and rod 253 attached to the arm we of stop 25 I.

With handle of lever 260, as shown, the jaw clutch 3 l--32 is heldengaged, and swung toward the left lifts rod 255, rotates member 254,exerts a pull on rod 253, to rock stop 25! out of the way of .lever 26lso that spring 61 may transmit force from lever 5| to release jaw 32from jaw 3|. This mechanism permits the direct drive clutch I 5 to beengaged while connecting turbine output member to the load shaft 20 fora braking effect derived from the resistance of the fluid in the torqueconverter.

From the foregoing, it is believed that a clear understanding is givenof the mechanism herein describing the invention, and its operation,especially in view of the references provided to the earlier filedapplications and patents of the applicant herein.

As outlined preceding, no claims are herein directed to the claimedsubject matter of the applicants patents and applications referred to,nor do the claims hereunder describe the inventions of said earlierfiled applications. The present application is more directly concernedwith the improvements provided here, and which produce new and usefulresults by the utilization of the features and expedients believed heredisclosed for the first time. Attention is especially directed to theadvantages provided in the new clutch control arrangement, whichobviates the difliculties formerly experienced with overrunning clutchesin drives of this type, and which yields a very positive control of thedriver over the movement of the vehicle at all times.

The particular arrangement of the forward and reverse gear unit whichprovides a complete idling of the countergear system during forwarddrive, is thought to possess points of novelty, as described in theclaims to follow. It is likewise believed that the added controldescribed in, conneetion with Fig. 8 for giving a new safety brakingfactor in negotiating hilly country, is of further utility and advantageover devices in this field disclosed in the prior art.

The control arrangement shown in Fig. wherein the dynamometric pressureresponsive switch S acts to sustain a higher ratio drive over low speedsand torques of the vehicle provides obvious advantages in lessening thewear and tear on the automatic shifting and selecting mechanism for thetransmission assembly. The sole-' noid operated mechanism forestablishing neutral drive through the positioning of the clutchactuator element 5| in Fig. 5, in conjunction with the positioning ofthe hand lever 240, for its operation of the switch S is felt to be ofimportance 'in the overall combination, as herein describedand claimed.The switch S6 consists of a bellows type contactor. spring'loaded torelease the circuit between $3 and S5 at low fluid pressures within theworking space of the torque converter, the unnumbered pipe being open tothe circuit flow space within the housing T of Fig. 1. V

There are further advantages having to do with structure such as that ofthe unit shown in Figs. 4 and 1 in section, but more particularly inFig. 4 which have to do with the relative longitudinal spacing of thesupporting hearing such as l2l, the overhanging portion of casing I00 atthe opposite end of the unit adjacent gear 43, and the sequentialstaging of mesh and demesh operationof the sliders 44 and 34 withrespect to the reverse-idler having'rings of teeth 41 and 48. I I

In the preamble to the specification I provide a series of generalizedstatements setting forth the utility and the objects of invention whichfeatures are claimed below, and are believed to represent novelcontributions to the art for not only thespace arrangement of the driveelements, but also the interlinked and interlocked controls, both manualand automatic, from which are derived new factors of higher safetyandincreased assuredness of operation in the heavy vehicle fleld, inparticular where the demand fo'r higher road speeds and faster ratiochangingpp'. erations in city trailic have become increasingly high.

While I have pointed out in the foregoing specification certain novelfeature ofinvention, it should be clearly understood that variousomissions, substitutions and changes of formand detail from theillustrative showing here, and in the operational relationships thereofmay be made by those skilled in the art without departing from the scopeof the invention. q Having thus described my invention, I claim: .1. Incompounded fluid and mechanical variable speed ratio transmissions, avariable speed transmission assembly including a fluid torque converteradapted to transmit the drive of an engine to a selective forward andreverse. gear unit coupled to a load shaft, an engine shaft, an impellermember of said converter, an input member for said unit, actuableclutching means coupling said engine shaft alternatively with saidconverter impeller or with the input member of said unit and including aclutch operativeffor coupling the output of said converter to the inputmember of said unit, controlled actuating means for said clutching meansoperableto effect the coupling of said engine shaft directly with saidunit input member and todisconnect said converter, or operable todecouple said engine from the input of said unit while coupling theinput of said converter to said engine and the output of said converterto the input of said unit,.and control means effective to cause saidactuating means to perform said coupling and decoupling. 2. In the.combination set forth. in. claim 1; a valve included in said controlmeans for said'ac-r tuating means, a controlling device for saidaotuating means, a connecting linkage between said movable member andsaid device effective to prevent operation of said actuating means whensaid member is moved to a predetermined position. i I 3. Inv thecombination set forth in claim 1, a power operated member included insaid actuat ing means and power controls for said member included insaid control means, the action of said member being effective upon apredetermined setting of said control means.-

4; In the combination set forth in claim 1, a positive jaw clutchincluded in said clutchin means which is operative for coupling theoutput member of said converter to the input member of said unit, saidjaw clutch having an operating link operated by the said actuating meansduring the coupling and uncoupling by said clutching means of saidengine and said unit input member.

'5. In the combination set forth in claim 1, a

positive jaw clutch included in said clutching means and having teethabutting during engagement and inclined to facilitate mesh for smoothtransfer of torque between the said torque converter output and the saidunit input. E6. in the combination set forth in claim 1,torquesuppo-rting gearing in a casing containing :lubricantincludedin'said unit and also including jaw clutch elements in said unit adaptedto transmit forward or reverse torque to said load shaft, said elementsbeing arranged for direct drive between said-unit input member and saidload shaft and for geared reverse drive therebetween, and of saidelements providing said direct drive while the'reverse drive elementscome to rest, whereby power'loss from churning of lubricant byidlinggear elements is avoided.

- '7. In a power transmission assembly for vehicle drives, a gearcasing, a forward and reverse gear unit in said casing "having a powerinput shaft, a concentric load shaft and a parallel countersh'aft, agear mounted on said power shaft, a second gear mounted to slide onsplines on said load shaft, a reverse idler gear body having two ringsof teeth and mounted on a shaft parallel to said other shafts, asliding. gear member mounted on said countershaft and constantly meshedwith one of said idler rings of teeth, an arrangement of longitudinalspacing of said gears and said rings of teeth such that when said secondnamed gear is moved longitudinally toward the point of emergence of saidload shaft fromsaid caslng;the gear-meshes with one of the :rings ofteeth of "said idler, and a connection coupling the said'second gearwith thesaid sliding member of said c'ountershaft "effective to meshsaid second gear with said member and thereby convert a forward torquecomponent applied to said input shaft into a reverse torque component onsaid loadshaft.

8, In the combination set forth in claim 7, mating jaw teeth on saidfirst and second gears to provide direct drive between said input andoutput shafts, a slider mechanism to slide said second gear toward meshthereof from the reverse drive positionstated in claim 7, andlongitudinal spacing of said gears and said rings of teeth such thatsaid second gear and said countershaft gear areboth demeshed from theteeth of said slider priorto'mesh of said jaw teeth providing the saiddirect drive.

9..In the combination set forth in claim 7, a common control means forsaid firstnamed sliding gear and said countershaft gear, an arrangementof longitudinal spacing of said gears and said rings of teeth such thatupon movement of said sliding gears toward mesh with the said rings ofteeth of said idler, the said countershaf t gear first meshes with saidfirst named input shaft gear; before subsequent mesh of said secondnamed gear with the-corresponding teeth of said idler.

In the combination set forth in claim '7, the said casing having a rearend bearing supporting the said output shaft, and adjacent splines on 12said output shaft extending longitudinally toward said bearing andoccupying the full co-planar zone in which lies the said second ring ofteeth of saidreverse idler gear.

11. In the combination set forth in claim '7, said casing having afore-end bearing supporting the overhanging portion of said power inputshaftupon which said first gear is mounted, and the said countershaftgear occupying a position approximately co-planar with said foreendbearing when sa'idsecond gear is moved oppositely to the position-statedin claim 7.

12. In power transmission devices, an engine, an enginespeed control, anengine shaft, a variable speed drive assembly driven by said engineshaft comprising concentrically placed powerand load shafts adapted tobe coupled directly or indirectly by a fluid torque converter, clutchmeans operable to couple said last named shafts and said converter,selectively operating controls for said clutch means arranged toestablish alternate direct drive or converter drive thereby, a clutchincluded in said clutch means and connected to said selectivelyoperating controls for coupling the said load shaft with the output ofsaid converter and for releasing same inresponse to'predeterminedselective operation of said controls a control link for operating saidclutch-connected to the said selectively operating controls providing anengaging and disengaging force conjointly with engaging and disengagingforce applied to another clutch of said clutch means, and of meshingpositive jaw clutch teeth forming the torquesupporting connectionbetween thesaid-converter output and the said load shaft.

13. In the combination set forth in claim 12, a forceapplying means forsaid clutch means consisting of a fluid servo piston and cylinder foroperation of said clutch means to providesele'ctive actuation for onecoupling drive combination and opposing spring means operative to storeenergy for another coupling drive combination of said clutch means, andcontrol means operated by said controls operative "upon saidforce-applying means and effective to apply a reactive force to saidengine speed control for predeterminedselective operations of saidcontrols involving the action of said clutch coupling the load shaftwith the output of said converter.

14. In the combination set forth in claim 12, a device responsive to thespeed and torque-operating conditions of the said torque converter andaconnection'from said device to said controls for superimposing "a ratioselecting and holding effect thereupon for certain values of saidconverter speed and torque expressed upon said device.

15. In power transmission controls, for motor vehicles, a transmissionassembly providing selec tive and automatic actuation of a plurality ofclutches for coupling a power shaft and a load shaft at variable speedratios consisting of a variable speed drive device having input andoutput members, a gear unit having input and output members, said gearunit output member being connected to said load shaft, a clutchadapted'to connect said power shaft to the input member of said device,a second clutch adapted .to connect said'power shaft to the inputmemberofsaid gear unit, .an actuator mechanism for saidfirst and secondclutches operable for alternate engage ment'of the clutches and movablebetween'clutch engaging positions wherein both clutches are 'disengaged,a control for'saidmechanism responsive to the speed of one of saidshafts and'operative tocause alternation of saidclutch engagement;

and a manual control element connected to said mechanism controloperative to. interfere with the automatic release of one of saidclutches'by mechanical blocking of movement'of said mechanism towardreleased position for said'one of said clutches. i I.

16. In control mechanisms, in combination, a

variable speed ratio transmission assembly adapt- 'ed to connect inputand output shafts and in cluding a variable speed drive device having anr output member and an input member, a gear unit having an input memberadapted to be driven by said device output member and having an out-1put member rotating with said output shaft, plurality of engageable anddisengageable clutches one of which is" arranged to connect said inputshaft'with said device input member and another of which is arranged toconnect said input' shaft with the said unit input member, a movableele-- ment for actuation of said clutches for establishingdrive in onespeed ratio or another between said shafts, forward and reverse'drivepaths'provided by said gear unit for coupling said output shaft to aload shaft, a movable control member for said unit operable to selectthe drive thru said 17. In the combination set forth in claim 16, a.

fluid-pressure actuator connected to said element for moving it to thesaid clutch drive and release positions, of valves'controlling theoperation of said actuator and subject to the action of said member thruthe agency of said connections, and of a mechanical relationship betweenthe motions of said element and said mechanism effective to oppose theclutch actuation'by said fluid motor thereon for a predeterminedpositioning of said mechanism.

18. In power transmissions for motor vehicles, an automatically operablevariable speed transmission assembly adapted to connect power input andoutput load shafts and including a fluid torque converter operative totransmit multiplied variable torque between said shafts, said converterincluding an impeller member, an output turbine member and atorqueereaction sustaining member,- said members being enclosed in ahousing within which a fluid pressure is generated varying with thetransmitted torque and. the relative member speeds of the converter;clutch means operative to connect said shafts directly or thru saidtorque converter impeller and turbine members, control means for saidclutch means operative to select actuation of said clutch means and adevice connected to a pressure space within said housing subject to thevariation of pressure therein created by rotation of said members andsaid device also being connected to said clutch control means forsuperimposing the efiect of the fluid pressure so derived upon theselective action of said control means.

19. A power transmission mechanism enclosed in a housing and couplinginput and output shafts at variable speed ratios, said mechanismincluding rotating members immersed in a fluid body contained in saidhousing and thereby generating within said housing a fluid pressurevarying with the speed and torque of said shafts, power transmittingmembers of said mechanism selectively up operable-"to provide selectivepaths of torque betweensaid shafts and actuators formoving said membersso as to establish the selective drivef'of said members automatic ratiocontrolsfor said actuators including an element operably'responisive tovarying speeds of one of said shafts, and a device responding to thesaid varying pres'sure within said housing'and effective "to modify thespeed-responsive operation of said automatic 'cbmtrols, effective'toestablish speed responsive-bentrol of ratio within one pressurerange'ofsaid device and for modifying the said speed responsive ratiochange action. at a different pressure range of said device.

20. A motor vehicle, an engine, a power transmission for driving saidvehiclefrom said engine embodying a fluid turbine torque converterhaviing input and output .rotor members adapted' to .transmit'variabletorque between power-and load shafts, clutching mechanism arranged-'tocon'nect the said members with said shafts respectively; a clutchadapted to connect the shafts directly,-se= lectively operableactuators" for said mechanism and said clutch, a control device forsaidactuators effective to cause alternate engagement of said mechanism fordrive by said converter or engagement of said clutch'for directdrive-between the said shafts, and a selective con-noradoperatingwithsaid'device subject tom'anual-operation and acting upon the saidactuatorfor-said mechanism effective to maintain the connection of'sa'id'converter turbine with the said load shaft during the period whensaid clutch actuatorjis causing the clutch to connect the shaftsdirectly, therefore providing the useful result-of a'braking effect uponthe said loadshaft in accordance with the selective action of saidcooperating control. 21. A fluid turbine torque converter adapted toconnect power and loadshaftshaving an input impeller and an outputturbinemembe'r, clutch mechanism for establishing said'connec tion, aclutch for connecting said shafts directly, an actuating'device for saidmechanism and said clutch effective for establishing alternate" driveeither by said mechanism and said converter or by said clutch betweensaid shafts, and aselective control subject to operatormanipulationoperative to preventsaid mechanism from disengag ing the torque of saidnutputturbine member when said clutch is engagedbythe action'of saiddevice. f 22. A power transmissionsy'stem' for connect ing power andload shafts including afluid tur bine torque converter having animpeller and a driven turbine, clutch mechanism for connecting samebetween said shafts, a clutch for con necting the said shafts directly,'actuatcr'nnkage normally operable to alternate the drive opera: tion ofsaid clutch mechanism with said clutch, and an interfering control forinterrupting the disconnection of the torque of said driven turbinewhile permitting the engagement of said clutch for the purpose ofproviding a hydraulic braking eifect derived from the resistance of saidturbine and acting upon said load shaft.

23. A fluid torque converter having a plurality of bladed rotorsenclosed within a housing containing a fluid body in a working space,one of said rotors being an impeller member adapted to generate acirculatory flow within the working space of the converter and anotherof said rotors being a turbine member adapted to receive a variabletorque from the said flow, power and load shafts, drive-connectingclutch mechanism operative to connect said shafts directly or;to..-connect"tthe :said impeller :and :turbine membersrespectivelyitosaid shafts, control de- M1665 effective to cause said: mechanism.to-..estab- Iiish said. shaft connections selectively, :and a pressureresponsive :apparatus subject to the {pressure -;generat.ed by therotation of saidirotors within said housingand operativeto. infiuencetheactionroi :said :control devices upon said mechanism.

124. In power drive devices ior transmitting variable torque betweenpower andload shafts, a ifluidtorque converter having an impeller,:reaction and output turbine rotor .members, :settable clutch mechanismfor connectingsaid impeller andturbine members .to said power andload-shafts respectively, a jaw clutch device of said mechanism arrangedto connect .said turfb'ine. member and said. load shaft when saidmechanism is. set. .to connect the shafts, .said device. consisting ofmating .engageable toothed elements having teeth with flat,torque-driving .i'aces andv inclined. end portions for rejecting mesh.during difierential speed intervals of said turbine'memberand said loadshaft for one hand 'of difierential rotation, control apparatus forsettingsaid mechanism to connect said turbine .member and said loadshaitincluding a resilient shifting member operable to bring said inclinedend portions of said teeth together for initial .contact and furtheroperable to seat the said toothed elements when at synchronous speed fordrive on saidflat tooth faces, said shifting member .being .likewiseoperable to release said elements when .said control. apparatus is setto release the said impeller .and turbine members.

, -f25.-.A power transmission mechanism enclosed in arhousing andadapted toconnect power transmitting input and outputshafts .at selectedvariablespeed ratios, .an-enginedriving said input shait, a speedcontrol for said engine, speed ratio selection means responsive to thespeed of one ofsaidshafts and adapted to change the drive ratio of.said. mechanism in order to increase saidratio with rise of speed, aconnection betweenisaid engine speed control .and saidspeed responsivemeans effective at advanced settings or. said engine speed control toselect drive by said mechanism at lower speed ratios than those selectedby said speed responsive means, and a dynamometric device responsive .tothe drive speeds and torques of said mechanism operative to prevent the.ratio controlling action of said engine speedrcontrol-and of .saidspeed responsive means during a predetermined range-oi speeds andtorques transmitted byzsaid mechanism.

.26. .In thecombination set forthin claim 25, the further arrangement of.said dynamometric device with said mechanism, wherein said mechranismincludes a fluid torque converter adapted to transmit torque betweenbladed .members eiiectively connected ".to said" .shaits, .throughtheagency of;a circulating body of .fiuid operating 'withinsaid converterat variable speeds -.and pressures, and the arrangement of said dyna-.mometric device including a :control element variably responsive to thechanges of pressure within said converter operative to prevent change ofdriveratio of said mechanism, at pressures below aminimum value, andlikewise operative toprevent said change of .ratio when the quantity .ofsaid liquid body within the converter diminishes below. a predeterminedamount.

27. A torque-transmitting drive assemblyzineluding .fluid.torqueconver-ter adapted to connect power and .1oad.:shafts,-.saidconverter-hav- .ing -aninput impeller and an output turbine member,clutch mechanism. for establishing said turbine connection to said.loadshait-aclutch .for connecting said shafts directlm. a :controllinkage operable to .engage said .mechanism and said clutchsimultaneously so that the torque upon .saidmechanism provides -.aturbine braking effect on the drive of said shaft, and .a control memberfor saidlinkage, movable to establish said braking eifect at the willofthe operator.

28. In the combination set forth in claimrlz wherein said control link.is-efiective for-operating said clutch and operating-said positivejaw;teeth which form the said torque supportingconnection of saidclutchmeans between the said converter output and the said-load shaft; thefurther combination of actuating means iorsaid control link embodying aresilient lost motion .mechanism for transmitting shifting forceoperative for .meshing .and. .demeshingsaid positive jaw teeth.

HANS O. SGHJOLIN.

.REFERENCES .CI'IED The following references are of record in the fileofthis patent:

UNITED STATES PATENTS Number Name Date 2,012,340 ;Emrick. Aug. 27 19352,109,610 .Austin Mar. 1, 1938 2,178,356 Brunner. Oct..31, v19392,280,002 Neracher ..r Apr. 14, 1942 2,282,591 .Orr May 12,19422,291,690 Caves 1.. Aug. v4, 1942 2,335,926 Fawick..- Dec. 7,19432,352,428 .Haliord .June 2'1, 1944 2,369,126 Baker Feb. 13, 19452,369,369 Peterson et a1. Feb. .13, 1945 2,435,930 Schjolin Feb. 10,1948

